To adjust the site in php

not a constructor. php 5.2

1. To correct the mail. Works, but not correctly.
2. Leaving the view in Explorer. There is a suspicion that the structure of the scripts is broken.
3. To verify the correct integration code, and clear the server-side code from all the excess.
4. Forgot password, cant log in to admin area (not on the server), and on the site itself.
5. Transfer domain hosting to another server. Then this domain to move the site from another domain (on same server)

Good knowledge of php, with experience.
No reaction to the problem: dont know, cant do this.